Drive mechanism for mechanical stokers



June '18, 1,935. v H' E .PREST'ON v 2,005,006

DRIVE MECHANISM FORMECHANICAL STOKERS Filed June 5L `195]. 5 Sheets-Sheet l June 18, 1935. E. PRESTON 2,005,006

DRIVE MECHANISM FOR MECHANICAL STOKERS Filed June 5, 1931 3 Sheets-Sheel 2 Fry-2 f,\

si Je my June 18, 1935. H. E. PRESTON lDRIVE MCHANISM- FOR MECHANICAL STOKERS 3 Sheets-Sheet 5 Filed'Jllne 5, 1931 Patented June 18, 1935 PATENT OFFICE DRIVE MEcHANlsM FoR MECHANICAL stroKERs i Herbert E. Preston, Philadelphia, Pa., assignor to American Engineering Company, Philadelphia, Pa., a corporation of `Pennsylvania Application June 5, 1931, Serial No.y 542,383

Claims.

This invention relates to.l improvements in mechanical stokers, and relates more particularly to improvements in the means for operating the fuel-feeding parts of a multiple retort undernfeed 5 4Stoker of the general character disclosed in `U. S.

l `provision for independent and' relative adjust- 'ments Aof the various driven parts.

The invention further resides in certain novel structural details hereinafter svet forth and illustrated in the attached drawings, in which:

' Figure 1 is a, sideelevational `View, lpartly in section with the pumping apparatus removed illustrating a Stoker drive made in accordance With my invention;

Fig. 2 is a vertical sectional view of the mechanism; I j Fig. 3 is a section on vthe line 3-3, Fig.- 2; Fig. 4 is a fragmentary sectional View showing details" o f the pusher-actuating rods and their supporting means; n I Fig. 5 is a fragmentary plan view illustrating a detailvof the rod connections, and Fg. 6 is a section on the 1in`e'6-6, Fig. 4; Fig. 7 is a partial plan view of the stoker structure showing a plurality of the retorts and the mechanism `associated therewith.

With reference to the drawings, I is the 'fr ont wall of a furnace equipped witha stoker made in accordance with my invention, and 2 is a ram housing secured against the outer face of the wall and provided-at the top with a port 3 which communicates with the bottom of a fuelhopper 4. Mounted for reciprocation within the housing 2 is a ram 5 which in anadvanced 'position as shown inthe drawings-effectively closes the'port 3, said ramwhen retracted permitting a gravity flow of fuel from the'hopper' 4 into the housing 2, which fuel'is projected by the ram in its next advance movement through vaport 6 in the front wall I ontofa dead plate 'I which constitutes the upper bottom portion of one'of a series of retorts \which with intermediate tuyres constitutes the fuel-supporting section of the Stoker whereo-n ciprocating eiiect a progressive movement of the fuel over the fuel-supporting section of the. stolzer. In the present instance, one only of the secondary or retort pushers 8 is illustrated.

As shown in Fig. 2, the ram ,5, which as will be apparent from the above description constitutesA one of a series of rams associated individually; with the respective retorts of the Stoker, is hollow and is open at its front end for reception of a piston II. The front end of the hollow ram, is closed by means of a head yI2 vvhichliasanv opening for passage therethrough of a rod I3, to 1 the rear end of which the said piston II is secured. In the present instance, the piston H' is threaded for reception of a `correspondingly threaded end of a rod I3. The vjoint between the Ahead I2 and the cylinder body is sealed by means of a suitable gasket, and suitable packing means is provided between the rod i3' and `the head I2 to prevent leakage yfrom the-interior of the ram. The rod I3 is rigidly secured at its outer end in a bracket I4 secured at its upper end directly to the housing 2, and at itsk forward and lower end to the outer end of anv extension bracket I5 attached to the lower forward portion of the housing 2. f

The rod i3, as illustrated in Fig. 3, is provided with two longitudinal passages I6 and I'l, respec-L tively, these passages communicating at theV forward or outer end of the rod, which as previously stated is iixed in the bracket I4, with' a pair ofy ducts I8 and I9 respectively, which connect to suitable uid-pumping apparatus designated generally bythe reference numeral 2l, see Fig. Y2, which in the present instance is mounted at the top of the bracket I4. The inner end of the pas sage I6 is closed in the present instance by means of a plug 22 threaded into the end of the rod I3, and this channel also has one or more ports Z3 which communicate with a countersunk recess 24 at the outerend of the piston II. This port 23 provides for application of fluid pressure between the piston II and the head I2 of the ram. The inner end of the passage Il communicates die rectly with lthe chamber at the inner end of the piston II and provides` for application of iluid pressure between the piston and the inner end of the hollow ram. Preferably,'the hollow ram, the passages I6 and Il and the ducts I8 and IQform with the pumping apparatus 2l a closed fluid circuit, andin operation the pump or pumps 2| operate simultaneously to evacuate the ram chamber at one side of the piston I I and to apply presm sure to the other side whereby the hollow ram is caused to reciprocate ,within the housing 2 inthe performance of the fuel-feeding function described above. The pumping apparatus 2'I may take the form of a reversible discharge pump which functions alternately to apply pressure and to evacuate the interior chambers of the ram. 5 at opposite sides of the piston to effect the aforesaid reciproca-tory movement of the ram.

The bracket extension I5 forms a journal for a rock shaft 25, to the opposite ends of which are secured levers 26. are secured through the medium of links 21 to opposite sides of the ram head I2, while between the lower ends of the said levers are pivotally mounted in the present instance a pair of blocks 28 and 28, each of which blocks isapertured for Y reception of one or more rods 3| and 32, respectively, and these rods 3| and 32 are connected through suitable couplings 33 to rods "34 and 35` are formed to 1 support and guide said rods.v

Each of the brackets is provided at its outer end with a recess 53 for reception of a suitable packing and a follower gland 54, which latter is held in position by means of studs 55 secured in the end of the bracket and extending through the fangel ofthe said gland. An efficient stuffing box is thus formed which effectively prevents leakage of air or dust from the interior of the Wall. At theinner end, each ofthe brackets is formed with an extension 56the inner end of which terminates in a bearing 51 for the respective rods. In that part which passes through the bearing, each of the rods is formed with a flat portion 58, see Fig. 6, which engages a segmental piece 59 secured in the associated bearing 51 by bolts 6I.

for the rods in the bearings while preventing any The arrangement affords a slidingfit angular or turning movement of the rods. The brackets 5| and 52 thus function not only to afford an extended supporting guide for the rods, but provide for sealing the joint where the said rods pass through the wall I and also incorporate means for preventing rotation of the rods from a normal position. The rods 34 and 35 are indi- Vidually secured to the rods 4I by means of pins 62, see Figs. 4 and 5, these pins being maintained in position in the bifurcated inner endsof the rods 34 and 35 by means of a wedge or equivalent element 63 inserted in an aperture 64 in the said ends of theV rods, this element engaging in a circumferential recess 65 in the pin 62, as shown in Fig. 4, and thereby preventing any axial movement of the pin in the supporting member. The

pins 62, however, may be readily withdrawn by first removing the element 63.

and the pushers. Frangible pins 66 may also be employed to secure the collars 45 and 46 to the rods 3| and 32.

Fig. 1 illustrates the method of connecting the.y rod 34 to the pusher 8, this connection consistl The upper ends of these leversV` the commonoperating lever 25.

The pins 62 may be adapted to fracture under a predetermined' strain to thereby constitute a safety element in' the transmission line between the prime mover' link 39 to the rod 34. Similar means may be employed for connecting the said rods to the other pushers of the retort, and preferably and as illustrated in Fig. 1, the rods 34 and 35 are provided with branches designated generally by the reference numeral 4I which prcyide independent connections for the individual fuel-feeding elements. These separate connectionsmay be adjustable if desired to permit individual adjustments of the secondary pushers with respect to the main actuating rods 34 and 35.

Means is also provided illustrated in Fig. 2 for adjusting these rods 31| and 35 with respect to Each of the rods 3| and 32 is provided with a collar 45 adapted to abut the inner sides of the blocks 28, and the outer endsof the rods are also provided with terminal collars 46. Intermediate the collars 45,

.the rods .are adapted for reception of one` or more horseshoe washers 41, the number and location of which determine the operative relation between the rods 3| and 32 and their respectiveI blocks. It will be noted that the primary ram 5 constitutes in itself the main actuating member posing the lever 26 between the ram 5 and the for the fuel-feeding elements, and that by ineroperating rods of the secondary rams, a highly flexible; connection is established affording a desired adjustment between the individual fuel-l feeding elements. v

It will be apparent that the invention-is notv limited to theparticular adjustment means herein described and illustrated, and that there may tort,`said `ram projecting at one end from saidcylinder, a plurality of fuel feeding pushers 1ocated in the bottom of said retort, hydraulic mechanism for actuatingthe ram, a plurality of rodsfand fixed guides therefor supporting the rods for longitudinal reciprocation, links connectpushers.

2. A mechanical stoker comprising a retorta;j cylinder associated with said retort, aram oper-` ating in said cylinder for feeding -fuel to saidY retort, said ram projecting at one end from said cylinder, a plurality of fuel feeding pushers located in the bottom of said retort, an actuating rod for each of said pushers, and means for supporting said rods for longitudinal reciprocatiom means operativelysconnecting the rods with theindividual pushers, lhydraulic mechanism for ac-ituating the ram, a lever having a fixed pivot and, operatively connected to the projecting end Yof, said ram at `a point substantially midway lie-- tween the top and bottom thereof, blocks pivota'lly mounted on said lever, and rods adjustable longitudinally in said blocks and pivotally connected with said first-named rods whereby actuation of the ram results in a predetermined actuation of said pushers.

3. A mechanical stoker comprising a retort, a cylinder associated with said retort, a ram operating in said cylinder for feeding fuel to said retort, said ram projecting at one end from said cylinder, a plurality of fuel feeding pushers located in the bottom of said retort, hydraulic mechanism for actuating the ram, actuating rods for the individual pushers, means for operatively connecting said rods with the pushers, and means including a lever operatively connected to the projecting end of said ram at a point substantially midway between the top` and bottom thereof for longitudinally reciprocating said rods in predetermined fixed paths in timed relation with the movement of said ram.

4. In a mechanical Stoker, the combination with a front wall of a furnace, of a fuel-supporting section extending inwardly from said Wall and comprising alternately arranged retorts and tuyres, openings in said wall providing access to the Lipper ends of the retorts, working cylinders secured to said front wall and communicating with said openings, a fuel hopper associated with each of said cylinders, a ram adapted for reciprocation in each of said cylinders. to feed fuel from said hopper into the retorts, one end of each of said rams projecting from the corresponding cylinder hydraulic mechanism for actuating said rams, a lever mechanism connected to the projecting end of each of said rams andmounted for oscillation by reciprocation of the latter, a'

plurality of fuel feeding pushers in each vof said retorts, an actuating rod for each of said pushers, fixed guides in said front wall for said rods wherein the rods are confined for longitudinal reciprccation, means for operatively connecting said rods with therespective pushers, and means for flexibly and adjustably connecting said rods with the said lever mechanism whereby vactuation of the ram results in a synchronized actuation of said pushers.

5. A mechanical Stoker comprising a fuel supporting section, including alternately arranged retorts and tuyres, a cylinder associated with each of said retorts, a plurality of rams, one vof said rams operating in each of said cylinders for y flexibly connecting said rods with said levers whereby actuation of the ram through the medium of the hydraulic mechanism results in an actuation of said pushers.

HERBERT E. PRESTON. 

